Understanding 1,4-Dioxane: Learning from PFAS for Regulatory Progress


Water utilities ensure the delivery of clean and safe drinking water to their communities by complying with state and federal guidelines. As they navigate the complexities of current water quality regulations to determine how to operate their facilities, they are also tasked with looking ahead by staying informed on emerging contaminants, their implications on regulatory updates, and the resulting changes to their water treatment process. An example of an emerging contaminant that warrants attention from water utilities is 1,4-dioxane. While no one is certain that 1,4-dioxane will follow the same regulatory path as per- and polyfluoroalkyl substances (PFAS), there are striking parallels between the two that water utilities nationwide should consider. As some water utilities have benefitted from preemptively preparing for the PFAS Maximum Contaminant Levels (MCLs), which are anticipated to be finalized by the EPA by the end of this year, water providers can begin to do the same as 1,4-dioxane makes headlines.

What is 1,4-Dioxane?

1,4-dioxane is a synthetic chemical primarily used as a stabilizer in industrial applications, such as solvents, detergents, and personal care products.  The compound enters the body through the consumption of contaminated air, water, and food, where it is metabolized. Short-term exposure to 1,4-dioxane can result in eyes, nose, and throat irritation, with long-term effects including kidney and liver damage. It recently gained attention due to its presence and persistence in American groundwater and its high potential to contaminate drinking water sources. Similar to PFAS,  it shows likely carcinogenic health effects as well. Although the Environmental Protection Agency (EPA), public water systems, and environmental scientists continue to monitor the compound and evaluate its risks, the growing health, awareness, and treatment concerns around 1,4-dioxane parallel the beginning of PFAS’ current regulatory path.

1,4-Dioxane: Following in the Footsteps of PFAS

1,4-dioxane shares many chemical and public health traits with PFAS, underscoring the need for proactive measures to address its contamination. Like PFAS compounds, 1,4-dioxane exhibits bio-persistency, meaning it remains in the environment for an extended period once released. Moreover, if left untreated, its remarkable solvency in water means it can quickly transport through groundwater, posing health risks not just to immediate contamination sites, but neighboring communities as well. Like PFAS, this currently unregulated water contaminant is found to be more prevalent than anticipated, with the nation’s ten largest wastewater facilities reporting 1,4-dioxane concentrations as high as 11,500 μg/L in their discharge monitoring reports to the EPA. This rapid spread, coupled with expensive treatment and remediation methods, calls for action from water utilities to anticipate growing awareness and future regulations in the coming years after the nation’s experience with PFAS contamination.

Is 1,4-Dioxane another 'Forever Chemical'?

Despite 1,4-dioxane’s similarities to PFAS, the compound differs in terms of chemical composition and behavior. PFAS compounds consist of carbon-fluorine bonds. They were designed to be extremely stable and resistant to degradation in harsh conditions that denature most other chemicals. By contrast, 1,4-dioxane does not possess the same level of chemical bond stability and breaks down under certain temperature, UV, and atmospheric conditions. Nonetheless, 1,4-dioxane is still resistant to biodegradation and exhibits stability in underground environments, which is why it specifically threatens groundwater sources.

So, while some consider 1,4-dioxane part of the "forever chemical" family that PFAS belongs to, this label does not accurately define the compound. However, it is crucial to acknowledge that 1,4-dioxane’s bio-persistency complicates on-site removal from contaminated water and soil. In combination with rapid spread, this means that time is of the essence to proactively identify, quantitate, and address any 1,4-dioxane contamination in ground water sources across the US.

Quick Spreading Contaminant

The rapid spread of 1,4-dioxane in groundwater can be attributed to various factors, including its solubility in water, lack of significant binding to the carbon in soil particles, and resistance to microbial degradation. Once released into the environment, 1,4-dioxane plumes expand rapidly through groundwater, potentially affecting large areas in a short amount of time. These characteristics mean the compound has the ability to cover larger areas at a faster rate than PFAS.

Public Awareness

News coverage and recent environmental regulations have made the public more aware of 1,4-dioxane contamination and its potential impact on health and water supplies. As more states act to regulate 1,4-dioxane ahead of the EPA, surrounding communities will also become more informed about the prevalence, persistency, and potential cancer risks associated with 1,4-dioxane. The public’s insistence to address this issue in your community or on a federal level may escalate as a result. In anticipation, water utilities can prepare to respond to community contamination concerns and actively participate in safeguarding their water supplies.

Already, increased public awareness of 1,4-dioxane contamination has been observed in front line communities in New York, Michigan, and North Carolina. In 2020, the state of New York’s health department issued a 1,4-dioxane MCL of 1 part per billion for their water providers to follow. Media coverage and the dissemination of scientific studies highlighting the presence of 1,4-dioxane in drinking water sources have contributed to the growing recognition of this issue as well. It is crucial to stay informed about public sentiment and actively engage with the community to address their concerns. Preemptively addressing contamination helps utilities gain public support for treatment funding and mitigates backlash.

1,4-Dioxane Water Treatment Solutions

While there are commercially available water treatment solutions for 1,4-dioxane contaminations, they require tailored methods that are different from those used to reduce PFAS levels. If 1,4-dioxane MCLs are released by the EPA or states in the future, water utilities will be required to find additional resources and funding to meet compliance, likely right after designing, constructing, and funding PFAS removal solutions. According to the EPA, advanced oxidation, and bioremediation are among the treatment methods known to effectively remove 1,4-dioxane from drinking water.

Advanced oxidation processes, such as ultraviolet (UV) light and hydrogen peroxide treatment, effectively break down 1,4-dioxane molecules into less harmful substances that are later removed or pass through the water treatment process.  Additionally, the feasibility of bioremediation techniques that leverage microbial activity to degrade 1,4-dioxane are being explored as potential “in-situ” solutions. Each treatment method has its advantages and considerations, and water utilities should consult a professional engineer to find the most suitable and up-to-date approach for their specific circumstances. The sooner this process starts, the more time and flexibility your water utility will have to choose its best path forward.

Secure an Early Seat at the Table

1,4-dioxane presents challenges similar to those posed by PFAS, considering its bio-persistence, rapid spread, and costly treatment methods. Water utilities should proactively monitor their water sources’ dioxane concentrations and consider the appropriate treatment solutions to ensure the continued delivery of clean and safe drinking water to their communities. By being informed and prepared, water utilities can continue to succeed in their crucial role of securing healthy water supplies for future generations. Remember, the early adoption of preventive measures can significantly mitigate the potential health and public relations risks associated with any water contamination, including 1,4-dioxane.

Looking back at the early days of the PFAS movement, those who took early action benefited from their proactive approach. Monitoring, public outreach, and treatment upgrades require buy-in from all water utility parties. But effectively securing a healthy water supply for your community requires staying ahead of the curve. By familiarizing yourselves with the emerging 1,4-dioxane contamination concerns and engaging in discussions about treatment and remediation strategies, you can make a significant difference in your community’s approach and relieve unnecessary stress if MCLs are released.

It remains to be seen whether 1,4-dioxane will follow the same regulatory path as PFAS, but some communities have already been obligated to invest in remediation and treatment, and many others may follow. Regardless of which treatment method is best for your water system, it will likely come with costs that you or your ratepayers may be forced to bear. If you suspect 1,4-dioxane has contaminated your water supply, it may make sense to explore whether litigation is the avenue to recoup some of those costs. SL Environmental specializes in contamination cases and works on a contingency fee, meaning your utility doesn’t incur legal fees until compensation is awarded.

Contact the team at SL Environmental Law Group to learn more about proactive measures and strategies to address contamination concerns.